Chuck for rock-drilling machines.



PATENTED DEC. 22, 1903.

APPLIOATION FILED JULY 1. 1903.

no 140mm.

UNITED STAT S Patented December 22, 1903.

PATENT OFFICE.

CHUCK FOFl ROCK-DRILLING MACHINES.

SPECIFICATION forming part of Letters Patent No. 747,423, dated December 22, 19 03.

Application filed July 1, 1903.

To all whom it may concern:

Be it known that LFREDERIOK HENDERSON, a subject of the King of England, residing at Johannesburg, Transvaal, have invented certain new and useful Improvements in the Oh ucks of Rock-Drilling Machines, (for which I have made application for patent in the Transvaal, No. 538, bearing date September 26, 1902,) of which the following is a specification.

This invention relates to the chucks of rock-drilling machines,and is designed to provide an efficient chuck of simple construction in which the defects of the existing devices will be eliminated.

In a chuck constructed in accordance with my invention I dispense with the ordinary U chuck-bolts, the breakage of which is of frequent occurrence, and consequently I avoid the expense of having to repeatedly replace the same. As compared with the existing chuck-bolts, the employment of my invention will effect a large reduction in the initial cost of manufacture as well as in maintenance, and a considerable saving of time will be efiected in the operation of changing or renewing the drills or drilling bits. I further provide means whereby the tightening of the drill or drilling-bit can be effected either top or bottom, and so permit of the wear being distributed at the top or bottom of the chuck-bush.

The invention will be fully described by aid of the accompanying drawings, in which Figure l is a front view of the chuck. Fig. 2 is a side elevation of the same. Fig. 3,is a transverse section of Fig. 2 on the line a; y, and Fig. 4 is a plan of the ring or hoop for retaining the parts in position.

The body or main part A of the chuck is formed on or fitted to the outer extremity B of the piston-rod or equivalent reciprocating member of the rock-drilling machine. The body A is formed of approximately cylindrical shape for the greater portion of its length and in proximity to the free end is constructed on two diametrically opposed sides thereof with two projections a a, which form two vabutments or shoulders partially round the body and beyond the abutments with a neck or extension I). The body A is formed with a longitudinal parallel and cen- Serial No. 163,885. (No model.)

tral hole 0, in which is fitted an ordinary bush or liner 0, adapted to receive the shank or extremity d of the drill or drilling-bit D, which is projected into it. The other two sides of the body A are made flat, as is indi cated at a in Fig. 3. In the flat faces a holes e e are formed communicating with the interior of the chuck-body A, and in the bush 0 holes 0 c are formed which coincide with the holes 6 e, formed in the body A. Thus when the bush cis in position ahole is formed transversely through the chuck intersecting the longitudinal parallel hole 0.

In the holes 6 6, formed in the bodyA and bush 0, are arranged two keys F F, which on the inside bear upon or engage the inner extremity or shank d of the drill or drillingbit D. The drill-shank is thus engaged .by

the pads F F both top and bottom or on two diametrically opposite sides. The bushing c and the keys F F on the inside are, in the drawings shown, constructed to accommodate steel of circular section; but it will be obvious that they may be shaped to receive any section of drill-steel, and so avoid the necessity for the swaging or shaping of the shank d of the drilling-bit D to fit the chuck.

Around the chuck-body A and encircling the two keys F F isa ring, hoop, or band G. (Shown in plan in Fig. at.) As isindicated at f, the exterior of the key F is curved to correspond to the inside of the ring G, which fits over or round it. The key F is also formed with an outward projection at one end, against which the ring abuts, which projection, in conjunction with the projections a 0/. on the body A, operates to retain the ring G and key F in position. The other key F protrudes from the body A and has its exterior face formed flat. In the ring G, immediately opposite the key F, is formed a semicircular or approximately semicircular recess 9. In the recess g is arranged a taper key or cotter H. The cotter H is, as shown in Fig. 3, curved onthe outside to fit the recess g and made flat on the inside to res upon the outer face of the key F."

The method of operating the device to fix or detach the drilling-bit D is obvious from the foregoing description. By forcing the cotter Hlongitudinally of the body A in one direction the keys F F are forced inward to grip the shank d of the drilling-bit D, and by moving the cotter H longitudinally of the body in the opposite direction the keys F F are freed and release the shank d of the drilling-bit D, permitting the drilling-bit D to be readily withdrawn and renewed.

\Vhat I claim as my invention, and desire to protect by Letters Patent, is-

1. In a rock-drilling-machine chuck, the combination of a hollow body portion, the same havinga hole formed therethrough,keys diametrically arranged in said hole and adapted to engage the shank of the drilling-bit, a ring surrounding said body portion and engageable with one of said keys, and a wedgeshaped cotter arranged between the other key and the ring, substantially as described.

2. In a rock-drilling-machiue chuck, the combination of a hollow body portion, the same having a hole formed therethrongh,keys diametrically arranged in said hole and adapted to engage the shank of the drilling-bit, a ring surrounding said body portion and engageable with one of said keys, an abutment on said body portion forming a stop for the ring against movement in one direction longitudinally of said body portion, a projection formed on one of said keys and acting as a stop for the ring against movement longitudinally of said body portion in the other direction, and a wedge-shaped cotter arranged between the other key and the ring, substantially as described.

In a rock-dfilling-machine chuck, the combination of a hollow body portion, the samehaving a hole formed therethrough,a key arranged in said hole and adapted to engage the shank of the bit, a ring surrounding said body portion, said key being adapted to take against the ring when engaged With the bit, and a wedge-shaped cotter arranged between said body portion and the ring in substantially diametric opposition to the key, substantially as described.

In witness whereof Ihave hereunto set my hand in the presence of two subscribing witnesses.

FREDERICK HENDERSON.

Witnesses:

J. E. MELLOR, OHAs. OVENDALE. 

